Literary usage of Capital of cameroon

Below you will find example usage of this term as found in modern and/or classical literature:

1.The Cold War & Beyond: Chronology of the United States Air Force, 1947-1997 by Frederick J. Shaw, Jr. (1998)"... of an ambulance to Douala, capital of Cameroon, and 31 pallets of medical
equipment to N'Djamena, capital of Chad—70 tons in all for both countries. ..."